This invention relates to ultraviolet curable coating compositions. More particularly, this invention relates to ultraviolet curable coating compositions having improved cure properties when used in conjunction with titanium dioxide-based pigments.
The problems concerned with using titanium dioxide pigments in ultraviolet-type applications have been recognized. See. U.S. Pat. No. 3,632,527.
U.S. Pat. No. 3,827,962 discloses the use of certain titanium dioxide-based pigments in ultraviolet curable coating compositions. However, the use of the applicants' unique compounds is not disclosed.
The use of titanium dioxide pigments in ultraviolet curable coating systems has been difficult, due to the ultraviolet reflection characteristics of titanium dioxide. The coatings utilizing these pigments are difficult, if not impossible, to cure under standard ultraviolet conditions. Coating line speeds, as a result have been substantially decreased, while costs have increased. Furthermore, even those curable systems containing low amounts of rutile titanium dioxide have been difficult to cure uniformly and exhibit poor substrate adhesion and chemical resistance.
It is an object of this invention to prepare ultraviolet curable coating compositions into which may be incorporated titanium dioxide without an attendant loss of coating adhesion and chemical resistance properties.
It is another object of this invention to prepare titanium dioxide-containing ultraviolet curable coatings which will cure under conventional curing conditions.
It is still another object of this invention to prepare and utilize novel polyunsaturated materials in an ultraviolet curable coating composition. These and other objectives are obtained by preparing the compositions of the instant invention.